Black Flies (Simuliidae)
No other biting flies cause such irritation as black flies. If you visit a Canadian forest in June and July you will see that this is justified. Black flies of the Simulium venustum species complex can be so numerous and their attacks so unrelenting that any outdoor activity during the day becomes almost impossible without protection.
Black flies often land and take off repeatedly without biting. Their number and their readiness to bite increases as sunset approaches. However, even when they are not biting, their buzzing presence and constant crawling is as irritating as the bloodsucking itself. Relief comes after dark, for unlike mosquitoes and biting midges (Culicoides sp), black flies do not attack at night.
Although they cannot bite through clothing, black flies have a predilection for crawling into hair or under clothing, biting in accessible places such as the ankles and belt line. Black flies are strongly influenced by colour – they find dark hues more attractive than pale ones and blue, purple, brown and black more attractive than white or yellow. A light coloured shirt therefore is a much better choice of clothing than a dark blue one.
Black flies are more selective in their choice of host than are mosquitoes and comparatively few species take human blood. Most species seem to feed only on the blood of birds and a substantial percentage apparently do not take blood at all because their mouthparts have degenerated.
No other biting flies cause such irritation as black flies. If you visit a Canadian forest in June and July you will see that this is justified. Black flies of the Simulium venustum species complex can be so numerous and their attacks so unrelenting that any outdoor activity during the day becomes almost impossible without protection.
Black flies often land and take off repeatedly without biting. Their number and their readiness to bite increases as sunset approaches. However, even when they are not biting, their buzzing presence and constant crawling is as irritating as the bloodsucking itself. Relief comes after dark, for unlike mosquitoes and biting midges (Culicoides sp), black flies do not attack at night.
Although they cannot bite through clothing, black flies have a predilection for crawling into hair or under clothing, biting in accessible places such as the ankles and belt line. Black flies are strongly influenced by colour – they find dark hues more attractive than pale ones and blue, purple, brown and black more attractive than white or yellow. A light coloured shirt therefore is a much better choice of clothing than a dark blue one.
Black flies are more selective in their choice of host than are mosquitoes and comparatively few species take human blood. Most species seem to feed only on the blood of birds and a substantial percentage apparently do not take blood at all because their mouthparts have degenerated.
